Electromagnetic pilot controlled valve system for main and auxiliary fuel lines



Aprll 20, 1954- BOOTH 2,675,828

ELECTROMAGNETIC PILOT CONTROLLED VALVE SYSTEM FOR MAIN AND AUXILIARY FUEL LINES Filed Sept. 18, 1948 2 Sheets-Sheet l Q Em [MERGE/V6) /4 [7 Ass 0/ 222 [6 41 V Mus Pump /Z/ 64 5a 65 as 54 INVENTOR BY? 2g: I

J ATTORNEY April 20, 1954 T. BOOTH ELECTROMAGNETIC PILOT CONTROLLED VALVE SYSTEM FOR MAIN AND AUXILIARY FUEL LINES Filed Sept. 18, 1948 2 Sheets-Sheet 2 N A w mux Q X .3 mm m mlwfi mm L V/ kw m m I u I U Q l A E LII I m NM L Q a q L6 m 8 L mm mm mm mm Q 1 a Q mm mm E NP b F n 8 HA El MN .L m mP 0b ATTORNEY Patented Apr. 20, 1954 ELECTROMAGNETIC PILOT CONTROLLED VALVE SYSTEM FOR MAIN AND AUXIL- IARY FUEL LINES Harry T. Booth, Dayton, Ohio, assignor to United Aircraft Products, Inc., Dayton, Ohio, a corporation of Ohio Application September 18, 1948, Serial No. 49,969

' erable selectively to combine the flows in parallel circuits.

The invention has especial, although not limited, application to the fuel supply systems of jet powered aircraft. Such systems ordinarily comprise a main supply line leading from a storage tank to the burner, and a parallel supply line for emergency use when the main line shall have \become disabled. Separate pumps in the lines are in continuous use in the operation of the system but the emergency pump normally functions merely repeatedly to circulate a small part of the fuel supply through a suitably controlled by-pass. It has been su gested that the existence of the emergency line in the system might be utilized to augment the volume of fuel supplied to the burner at times when that is desirable, for example, as when starting the engine. The present invention contemplates a reduction to practice of that idea, whereby a valve device is embodied in the system selectively operable to direct the output of th emergency pump to the main supply line.

To modify the conventional fuel supply system in this respect is an object of the invention.

Another object is to present, for a use such as that described, a fluid flow control valve characterized by a pilot valve initiated pressure differential action by which the fluid flow is directed through alternative parallel circuits.

A further object of the invention is to utilize the low pressure comiection defined by the normally open by-pass in the emergency line in attaining the pressure differential for operation of the valve device.

Still another object is to provide for simplified, remote operation of the valve device by placing the pilot valve under the control of an electromagnet unitarily assembled with the valve device.

Other objects and structural details of the invention will appear from the following description when read in connection with the accompanying drawings, wherein:

Fig. 1 is a diagram of a fuel supply system in accordance with th invention;

Fig. 2 is a view in vertical longitudinal section of the valve device diagrammatically indicated in Fig. 1;

Fig. 3 is a view in cross section taken substantially along the line 33 of Fig. 2; and

Fig. 4 is a fragmentary view, showing the pilot valve mechanism in enlarged scale.

Referring to Fig. 1, a fuel system embodying a valve device in accordance with the present invention may comprise a storage tank l0 and a burner ll. Fuel from the tank In is supplied to the burner l l by Way of a first or main pipe line E2 or by way of a second or alternative pipe line comprised of sections l3 and [4. A pump I5 is disposed in line [2 for withdrawing the fuel from the tank It and delivering it under pressure to the burner H. A similar pump I6 is disposed in alternative pipe line section [3. The pipe line 12 and the line l3-l4 are arranged in parallel relation and represent respectively primary and emergency systems. The pumps I5 and i6 operate continuously. The output of the latter normally is icy-passed, however, there being provided in section it of the emergency system a valve I? normally adjusted to direct flow back to the inlet side of the pump it by way of a by-pass conduit !3. Should the primary supply system fail to function, valve I! is adjusted to close by-pass conduit 5 8 to permit fuel to be supplied to the burner by way of the emergency pipe line IS-hi.

According to the present invention there is interposed between the emergency pipe line sections l3 and is a valve device [9 operable to direct the-output of pump [6 alternatively to emergency pipe line section [4 or to the main pipe line l2 by way of a conduit 2|. As before set out, the function of the valve device I9 is to permit the outputs of the pumps 15 and It to be combined when that is desirable in the operation of the system.

Considering the valve device IS in greater particularity, and referrin to Figs. 2 and 3, it is seen to comprise a body 22 which is roughly cylindrical viewed in end elevation except for an upstanding boss portion 23. The body 22 presents an inlet opening is receiving the outer end of emergency pipe line section it and a pair of outlet openings 25 and 26 respectively receiving the adjacent ends of emergency pipe line section [4 and by-pass conduit 2|. Formed longitudinally within the body 22 is a bore 21, the inlet 24 being disposed at right angles to the bore 2? and opening thereinto. At the opposite ends of bore 21 are counterbores 28 and 29 respectively closed by caps Si and 32 screw threaded therein. At or adjacent to the bottom of counterbore 28 is an annular groove 33 communicating with outlet opening 25. Within counterbore 29 is a similar groove 34 communicating with outlet opening 26. Received in counterbore 28 is a sleeve or bushing 35 seating at its inner end upon the bottom of the counterbore and received in a slight recess concentric with bore 21. The opposite or outer end of the sleeve 35 has a projecting portion of reduced diameter substantially in contact with cap 3i and defining an annular space 36 therearound. A set of radial ports 31 in sleeve 35 registers with groove 33 so that fluid may pass from bore 27 to groove 33 and outlet 25. Slidable within the sleeve 35 to control fluid flow between the bore 2? and outlet 25 is a check valve 38. The valve 33 is constructed and arranged to seat upon the bottom of counterbore 28, being formed on its inner peripheral edge with a chamfer engageable with the edge defining bore 2i. Valve 38 is urged to a seated or closed position within bore 2i by a spring 33 received in complementary recesses in the cap 3! and the valve 38.

Valve 38 has a relatively long bearing in the sleeve 35 and functions as a piston to define in conjunction with cap ti a fluid pressure chamber ll rearwardly of the valve. Communication between the chamber ii and the groove 33 is precluded along the inner surface of the sleeve 35 by reason of the sliding fit of valve 33 within the sleeve and is precluded along the outer sur-- face of the sleeve by a ring seal :32 recessed within a radial groove in counter-bore 23. The chamber ii is connected to the aforementioned annular space 36 by one or more notches d3 cut in the outer end of the sleeve 35.

An assembly of parts similar to that above de scribed is mounted in counterbore 2%. Thus ther is arranged in this counterbore a sleeve or bushing lie having radial ports 55 registering with groove 3 Slidable within the sleeve is a piston-like check valve 46 urged to a seated position closing the adjacent end of bore 2'5 by a spring Further the valve (i6 defines in conjunction with the cap 32 a pressure chamber 48 communicating with an annular space cs surrounding the outer end of the sleeve 44. The formation of valve 66 difiers from that of valve 36 in that the former engages the bottom of counterbore so in surrounding, radially spaced relation to the edge of bore 2? and has a substantial bearing in that portion of sleeve 4i! inward of the ports 45. The construction and arrangement is such as to prevent reverse flow from the outlet 26 to the bore 2'! in the closed position of valve 46, the outlet 26 being connected to an area of high pressure as represented by main supply line it.

The tension of the springs 39 and il acting upon valves 33 and 45 is such as to permit these valves to open under the normal pressure developed by emergency pump l6 and transmitted to the faces of the valves through inlet opening 2s and bore 2?. A selective opening and closing of the valves is accomplished by creating relatively difierent pressure differentials across the valves.

Within the boss 23 of the body 22 and disposed at right angles to the bore 2! is a bore and a counterbore 52. The bore 55 connected by a passage 53 to the groove 33. The counterbore 52 is connected by a first passage 5 to the bore 2?, by a second passage 55 to the annular space 38 communicating with pressure chamber dl in back of valve 38 and by a third passage to the annular space 49 communicating with pressure chamber 48 in back of valve is. The passages 5d, 55, and 56 are vertically spaced from one another along the length of counterbvore 52 and in some instances are formed by a plurality of drilling operations as indicated in the drawings. Wthin the counterbore 52 is a bushing 51 having its nner end resting upon the bottom of counterbcre and being formed with an outer end of relatively greater diameter screw threaded into an enlargement of counterbore 52. The outer extremity of the bushing 5? is formed as a flange Eli-i overlying the boss 23. The external surface or" that portion of bushing 5'5 lying within counterbore i spool-like, being provided with a plurality of spaced circumferential grooves receiving ring seals ill (see also 4+). The ring seals ti in grooves 59 prevent the passage of fluid along the bushing 51 externally thereof and lie in alternating spaced relation to other bushing grooves E 2, i3, and kid. Groove 62 registers with and is in. communication with passage 55 While grooves 63 and es respectively register with and communicate with passages 54 and Each groove 62, 63 and 64 further communicates with the interior of bushing 52 through associated radial ports therein.

In nested relation to the bushing 5? is a pilot valve filiformed with longitudinally spaced external flanges 5E and ill. The flanges t t and 57 in sliding and sealing contact with the internal suriace of bushing 5?, the remainder of the body of the valve being radially spaced from the The pilot valve 55 normally limits against is bottom of counterbore 532 and formed with a central longitudinal bore 68 registering and communicating with bore 5!. There is further formed in the valve 65, adjacent the outer end thereof, a set of radial ports 59 normally registering with bushing groove 52 and associated set of radial ports. The construction and arrangement of the parts of the pilot rave assembly thus is such as to enable the pass 55 and 53, connected to the pressure chaina re all and ii, to be alternatively connected to re a low pressure area or drain. It will be recalled that outlet 255 communicates with pipe line secticn i leading to the normally open by-pass conduit H3. Passage 5 by reason of its connection to bore 2? represents a connection to a high pressure area, bore 2? being in communication with inlet opening 24.

Valve 65 is operated by an electromagnetic device ill lockw-ired or othe wise securely mounted upon flange 58 of bushing 5 This device includes a casing H surrounding a coil M which is wound upon a spool defined by spaced end plates l3 and M. A cap is mounted upon end plate i3 and supports a connector through which electrical leads 1? are passed and connected to coil 12. Reciprocable within coil '12 is a plunger 18 having a stem-like outer end formed with an integral plate is received in the counterbored oute' end of pilot valve 65 and connected thereto by a retaining ring 8!. Plate iii is loosely received in the valve 65 to allow for error in the aligning of bushing 5'5 and the electromagnetic device. The plunger 18 is urged by a spring 82 based upon plate 73 downward or in a direction to seat valve 65 upon the bottom of counterbore 52.

In Figs. 2 and 3 the valve device is shown with the parts in the position they assume when the pumps l5 and 16 are idle and the electromagnetic device 1!] is de-energized. When the pumps l5 and it are started they begin respectively to direct fuel from the tank In to the fuel burner ll by way of pipe line l2 and to the valve device it by way of emergency pipe line section l3. The output of emergency pump l6 enters the valve device 19 by way of inlet 24 and is introduced thereby into the bore 21 where it acts upon the opposed check valves 38 and 46. As a part of the same operation by which the pumps [5 and I6 are started, or by separate concomitant opera tion, the electromagnetic device may be energized. In response to such energization, the coil l2 sets up a magnetic attraction inducing plunger '58 to move upwardly or rearwardly within the coil against the urging of spring 82. The pilot valve 65 is constrained to follow suchmotion with the result that the external flanges 66 and 61 thereon are moved from a point immediately below the respective grooves 62 and 64 in the bushing 5! to a point immediately above such grooves. In this position of the parts the groove 62 is connected by the space between the flanges 66 and 61 to the bushing groov 63 communicating with passage 54, and the groove 6-4 communicates around the lower end of the pilot valve with bore 5! and passage 53. Accordingly, the fluid pressure developed in bore 21 by the operation of pump I6 is transmitted through passage 54, groove 62 and passage 55 to the pressure chamber ll in back of valve 38. The pressure chamber as in back of valve 46 is at the same time connected through passage 56, groove 64, bore 5| and passage 53 to the annular groove 33 and outlet 25, the outlet 25 functioning at this time as a drain. Thus the inlet pressure acting upon valve 68 within bore 21 in a direction to open this valve is balanced by an opposing fluid pressur of substantially equal magnitude in chamber 4| tending to close the valve. It will be observed that the front and rear surfaces of the valve 38, as well as those of the valve 46 expose approximately equal areas to the action of the fluid pressures. The pressures on the opposite sides of valve 38 being balanced, the spring 39 is effective to maintain this valve closed. In the case of valve 6, however, there is a pressure differential on the opposite sides thereof corresponding to the difference in pressure between the bore 21 and the outlet 25. Under the influenc of such pressure differential, valve 46 is caused to open and the fluid entering bor 21 is permitted to pass to outlet 26 from whence it is directed by Way of conduit 2! to the main pipe line I2. The outputs of the pumps l5 and [6 thus are at this time combined and their total volume delivered to the fuel burner II by way of pipe line l2. When desired or when it is no longer necessary to supply an augmented quantity of fuel to the burner the electromagnetic device 10 is de-energized. When this occurs the plunger 18 is allowed to descend under the urging of spring 82 to restore the pilot valve 65 to the position shown in Fig. 2. In so moving, the external flanges 66 and 6? thereon are moved from a position immediately below those grooves. In consequence the fluid connections previously described by which check valve 46 was permitted to open are reversed. Thus passage 56 communicating with pressure chamber 48 in back of valve 46 now is connected to groove 63 and the source of high pressure by way of passag 54. Similarly, passage 55 communicating with pressure chamber 4! in back of valve 38 is connected by way of ports 66 in the valve 65 and central passage 68 therein with passage 53 and low pressure outlet 25. With the parts so positioned, therefore, the fluid pressures on the opposite sides of valve 46 are balanced and this valve is held closed by spring 41. A pressure differential exists, however, on the opposite sides of valve 36 so that this valve is allowed to open and the fluid entering bore 21 is permitted to discharge through outlet 25. From outlet 25 the fluid passes through emergency pipe line section [4 to valve H from whence it is recirculated by way of by-pass l8 back to the pump [6 until such time as it may become necessary to utilize the emergency system to supply the fuel burner l I.

It will be understood that in utilizing the out let 25 as a drain to secure a pressure differential across a selected valve 38 or 46 advantage is being taken of the most immediately accessible low pressure area. It would be possible to provide a separate drain back to the tank In or to the inlet of pump l6, or to connect drain passage 53 to some other point of low pressure in the system. The requirement merely is that a pressure differentia1 be established on opposite sides of a valve 33 or 46 suflicient to overcome the springs 35 or 41.

What isclaimed is:

1. In a fuel supply system flowing fuel under pressure, a valve device comprising a body presenting an inlet and a pair of outlets, a valve at each of said outlets closing in a direction opposed to the direction of flow from said inlet, a spring urging each of said valves closed, said springs being constructed and arranged to be overcome by the fluid pressure at said inlet, and means including appropriate passages and a valve controlling said passages for alternatively communicating said inlet with the rear faces of said valves to balance the effects of fluid pressure thereon and to permit flow from said valve device through a selected one of said outlets.

2. In a fuel supply system, flowing fuel under pressure, a valve device presenting an inlet and a pair of outlets, a bore in said body communicating intermediate its ends with said inlet and at its opposite ends with said outlets, counterbores in the opposite ends of said bores, closures for said counterbores, a valve movable in each said counterbores to and from a seat on the bottom thereof to close and open a respective end of said bore, a spring urging each of said valves to closed position, said springs being constructed and arranged to be overcome by the fluid pressure admitted to said bore by way of said inlet, and means including appropriate passages and a valve controlling said passages for alternatively communicating said bore with said counterbores rearwardly of said valves to balance a selected one of said valves against the effects of fluid pressure.

3. In a system flowing fluid under pressure, a valve device presenting an inlet and a pair of outlets, and a low pressure or drain connection which may be comprised in one of said outlets, a valve controlling each of said outlets and closing in a direction opposed to the direction of fluid flow, a spring urging each of said valves to closed position, said springs being constructed and arranged to be overcome by the fluid pressure at said inlet, means defining a fluid pressure chamber rearwardly of each of said valves, and means for alternatively connecting said pressure chambers to said inlet and said drain, said means including a plurality of passages respectively communicating with said pressure chambers, said inlet and said drain, and a valve settable selectively to connect said inlet and drain passages to said pressure chamber passages.

4. In a system flowing fluid under pressure; a valve device comprising a body presenting an inlet, a pair of outlets in communication with the inlet, and a low pressure or drain connection which may be comprised in one of said outlets, a spring loaded check valve controlling each or" said outlets and closing in a direction opposed to the direction of fluid flow, said valves tending to open under the influence of fluid pressure at said inlet, means defining a fluid pressure chamber rearwardly of each of said valves, a valve bore in said body, fluid passages opening into said valve bore and respectively communicating with said inlet, said drain connection and said pressure chambers, and a pilot valve movable in said bore to connect said inlet selectively to one of said pressure chambers and simultaneously to connect the other of the pressure chambers to said drain.

5. A system according to claim 4 characterized by spring means tending to maintain said pilot valve in a first operating position in which the fluid pressures on opposite sides of one of said check valves are balanced, and electromagnetic means mounted on said body operable when energized to move said pilot valve to a second operating position to reverse the fluid connections to balance the fluid pressures acting on the other one of said check valves.

6. In a system flowing fluid under pressure, a valve device comprising a body presenting an inlet communicating with a source of fluid under pressure, first and second outlets in said body communicating with said inlet and, opening respectively into areas of low and high pressure, a spring loaded check valve controlling each of said outletsand closing in a direction opposed to the direction of fluidflow, said valves tending to open under the influence of fluid pressure at said inlet, means defining a. fluid pressure chamber rearwardly of each of said valves, a valve bore in said body, a. passage connecting each of said fluid pressure chambers to said valve bore and other passages connecting said inlet and said low pressure outlet to said valve bore, and a pilot valve settable to first and second positions in said valve bore to interconnect said passages in such Wise as to balance the fluid pressures acting upon a selected check valve Whereby to maintain said valve closed and permit fluid flow from said inlet to occur past the other check valve.

'7. A system according to claim 6, characterized in that the check valve associated with the outlet communicating With the area of high pressure is provided with a seating surface inhibiting the escape of back-pressure thereby.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 537,584 Rockwell Apr. 16, 1895 2,263,913 Bargeboer Nov. 25, 1941 2,279,571 Kane Apr. 14, 1942 2,316,445 Marshall Apr. 13, 1943 2,375,411 Grant 1- May 8, 1945 2,379,181 Pontius June 26, 1945 2,394,431 Curns et a1. 1 Feb. 5, 1946 2,447,820 Schutz Aug. 24, 1948 2,479,359 Holt Aug. 16, 1949 

